TRACKING MEMORY MAPPING TO PREVENT PACKERS FROM EVADING THE SCANNING OF DYNAMICALLY CREATED CODE

To detect possible malicious code that is unpacked at runtime before it is executed, antivirus software requires that any dynamically created code be scanned before it can be executed by a host computer system. This requirement may be enforced by requiring memory pages to be either executable or writable, but not both. Before changing from writable but not executable to executable but not writable, the page is scanned for malicious code. To prevent packers from evading this scanning, a countermeasure tracks the memory mapping in the host system to enforce consistency in the protection settings for all memory spaces that are mapped to the same physical memory page.